Meet the mesonychids
There’s one clade of placental mammals
that few are interested in. That may be because they are a confusing lot, difficult to determine internal and external affinities.
They are all extinct today.
These are the mesonychids
(Fig 1) and they are largely known from skulls. Some were likely carnivores. Others were likely dog-like to hippo-like herbivores with hooves.
Basal taxa were tiny. Derived taxa were huge.
Figure 1. The LRT clade of mesonychids, including Mesonyx and Andrewsarchus.
” data-medium-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/06/harpagolestes_macrocephalus_andrewsarchus_sinonyx_to_scale588-1.jpg?w=124″ data-large-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/06/harpagolestes_macrocephalus_andrewsarchus_sinonyx_to_scale588-1.jpg?w=423″ class=”size-full wp-image-86780″ src=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2024/06/harpagolestes_macrocephalus_andrewsarchus_sinonyx_to_scale588-1.jpg” alt=”Figure 1. The LRT clade of mesonychids, including Mesonyx and Andrewsarchus.” width=”584″ height=”1413″ />
Figure 1. The LRT clade of mesonychids, including Mesonyx and Andrewsarchus.
Where does this clade nest?
That depends on what day it is. Today it is the Carnivora. These taxa finally nest together. That seems stable. Where they nest together changes when rescoring distantly related taxa. That’s the reality of the Carnivora and the Placentalia n the LRT. That’s the challenge.
Since these are all terrestrial taxa,
the large ones probably evolved after the asteroid impact, giving placentals the second of their two radiations. The first radiation of tiny taxa occurred during the Middle Jurassic and produced only arboreal taxa (according to the present data, depending largely on size , currently lacking post-crania). That second radiation might be the reason why mesonlychids sometimes nest as basal placentals. Other times they nest within Carnivora. Still other times some nested basal to large-bodied herbivorous placentals.
Seeking a little assistance from Wikipedia – Mesonychidae
they report, “Mesonychidae (meaning “middle claws”) is an extinct family of small to large-sized omnivorous-carnivorous mammals. They were endemic to North America and Eurasia during the Early Paleocene to the Early Oligocene, and were the earliest group of large carnivorous mammals in Asia. Once considered a sister-taxon to artiodactyls, recent evidence now suggests no close connection to any living mammal.”
See what I mean? 1) “Carnivorous” and 2) “basal to artiodactyls” and 3) no close connection. That’s why work continues on the placental subset of the LRT.
“Mesonychid taxonomy has long been disputed and they have captured popular imagination as “wolves on hooves”, animals that combine features of both ungulates and carnivores.”
Mesonychidae is a difficult clade to understand. For everyone.
Let’s not forget that hippos have huge canines and hooves.
PS
For those interested in elephant ancestors, that recent post was updated yesterday. Now hooved, herbivorous Coryphodon is the ancestor with saberteeth.
References
https://en.wikipedia.org/wiki/Mesonychidae
Source: https://pterosaurheresies.wordpress.com/2024/06/19/meet-the-mesonychids/
Anyone can join.
Anyone can contribute.
Anyone can become informed about their world.
"United We Stand" Click Here To Create Your Personal Citizen Journalist Account Today, Be Sure To Invite Your Friends.
Humic & Fulvic Liquid Trace Mineral Complex
HerbAnomic’s Humic and Fulvic Liquid Trace Mineral Complex is a revolutionary New Humic and Fulvic Acid Complex designed to support your body at the cellular level. Our product has been thoroughly tested by an ISO/IEC Certified Lab for toxins and Heavy metals as well as for trace mineral content. We KNOW we have NO lead, arsenic, mercury, aluminum etc. in our Formula. This Humic & Fulvic Liquid Trace Mineral complex has high trace levels of naturally occurring Humic and Fulvic Acids as well as high trace levels of Zinc, Iron, Magnesium, Molybdenum, Potassium and more. There is a wide range of up to 70 trace minerals which occur naturally in our Complex at varying levels. We Choose to list the 8 substances which occur in higher trace levels on our supplement panel. We don’t claim a high number of minerals as other Humic and Fulvic Supplements do and leave you to guess which elements you’ll be getting. Order Your Humic Fulvic for Your Family by Clicking on this Link , or the Banner Below.
Our Formula is an exceptional value compared to other Humic Fulvic Minerals because...
It’s OXYGENATED
It Always Tests at 9.5+ pH
Preservative and Chemical Free
Allergen Free
Comes From a Pure, Unpolluted, Organic Source
Is an Excellent Source for Trace Minerals
Is From Whole, Prehisoric Plant Based Origin Material With Ionic Minerals and Constituents
Highly Conductive/Full of Extra Electrons
Is a Full Spectrum Complex
Our Humic and Fulvic Liquid Trace Mineral Complex has Minerals, Amino Acids, Poly Electrolytes, Phytochemicals, Polyphenols, Bioflavonoids and Trace Vitamins included with the Humic and Fulvic Acid. Our Source material is high in these constituents, where other manufacturers use inferior materials.
Try Our Humic and Fulvic Liquid Trace Mineral Complex today. Order Yours Today by Following This Link.
![Report abuse](/img/report_abuse.png)